Control: 6.2.5 Ensure that the 'Log_min_messages' Flag for a Cloud SQL PostgreSQL Instance is set at minimum to 'Warning'

Description

The log_min_messages flag defines the minimum message severity level that is considered as an error statement. Messages for error statements are logged with the SQL statement. Valid values include DEBUG5, DEBUG4, DEBUG3, DEBUG2, DEBUG1, INFO, NOTICE, WARNING, ERROR, LOG, FATAL, and PANIC. Each severity level includes the subsequent levels mentioned above. ERROR is considered the best practice setting. Changes should only be made in accordance with the organization's logging policy.

Auditing helps in troubleshooting operational problems and also permits forensic analysis. If log_min_messages is not set to the correct value, messages may not be classified as error messages appropriately. An organization will need to decide their own threshold for logging log_min_messages flag.

This recommendation is applicable to PostgreSQL database instances.

Remediation

From Console

1. Go to the Cloud SQL Instances page in the Google Cloud Console by visiting https://console.cloud.google.com/sql/instances
2. Select the PostgreSQL instance for which you want to enable the database flag.
3. Click Edit.
4. Scroll down to the Flags section.
5. To set a flag that has not been set on the instance before, click Add item, choose the flag log_min_messages from the drop-down menu and set appropriate value.
6. Click Save to save the changes.
7. Confirm the changes under Flags on the Overview page.

From Command Line:

1. Configure the log_min_messages database flag for every Cloud SQL PosgreSQL database instance using the below command.

gcloud sql instances patch <INSTANCE_NAME> --database-flags log_min_messages=<DEBUG5|DEBUG4|DEBUG3|DEBUG2|DEBUG1|INFO|NOTICE|WARNING|ERROR|LOG|FATAL|PANIC>

Note: This command will overwrite all database flags previously set. To keep those and add new ones, include the values for all flags to be set on the instance; any flag not specifically included is set to its default value. For flags that do not take a value, specify the flag name followed by an equals sign ("=").

Default Value

By default log_min_messages is ERROR.